MFC r296286,r296470,r296472,r296473,r296575:

  r296286:
    Remove filemon->lock wrappers.
  r296470:
    Only call bwillwrite() for logging to vnodes, as other fo_write() calls do.
  r296472:
    Require kldunload -f to unload.
  r296473:
    Add missing break for r296472.
  r296575:
    FILEMON_SET_FD: Disallow changing the fd.

1 files changed, 16 insertions, 8 deletions

diff --git a/sys/dev/filemon/filemon.c b/sys/dev/filemon/filemon.c
index 352f682..e33536f 100644
--- a/sys/dev/filemon/filemon.c
+++ b/sys/dev/filemon/filemon.c
@@ -71,8 +71,6 @@ extern struct sysentvec elf64_freebsd_sysvec;
 static d_close_t	filemon_close;
 static d_ioctl_t	filemon_ioctl;
 static d_open_t		filemon_open;
-static int		filemon_unload(void);
-static void		filemon_load(void *);
 
 static struct cdevsw filemon_cdevsw = {
 	.d_version	= D_VERSION,
@@ -130,7 +128,7 @@ filemon_dtr(void *data)
 
 		/* Follow same locking order as filemon_pid_check. */
 		filemon_lock_write();
-		filemon_filemon_lock(filemon);
+		sx_xlock(&filemon->lock);
 
 		/* Remove from the in-use list. */
 		TAILQ_REMOVE(&filemons_inuse, filemon, link);
@@ -143,7 +141,7 @@ filemon_dtr(void *data)
 		TAILQ_INSERT_TAIL(&filemons_free, filemon, link);
 
 		/* Give up write access. */
-		filemon_filemon_unlock(filemon);
+		sx_xunlock(&filemon->lock);
 		filemon_unlock_write();
 
 		if (fp != NULL)
@@ -165,13 +163,15 @@ filemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag __unused,
 	if ((error = devfs_get_cdevpriv((void **) &filemon)) != 0)
 		return (error);
 
-	filemon_filemon_lock(filemon);
+	sx_xlock(&filemon->lock);
 
 	switch (cmd) {
 	/* Set the output file descriptor. */
 	case FILEMON_SET_FD:
-		if (filemon->fp != NULL)
-			fdrop(filemon->fp, td);
+		if (filemon->fp != NULL) {
+			error = EEXIST;
+			break;
+		}
 
 		error = fget_write(td, *(int *)data,
 #if __FreeBSD_version >= 900041
@@ -198,7 +198,7 @@ filemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag __unused,
 		break;
 	}
 
-	filemon_filemon_unlock(filemon);
+	sx_xunlock(&filemon->lock);
 	return (error);
 }
 
@@ -308,6 +308,14 @@ filemon_modevent(module_t mod __unused, int type, void *data)
 		error = filemon_unload();
 		break;
 
+	case MOD_QUIESCE:
+		/*
+		 * The wrapper implementation is unsafe for reliable unload.
+		 * Require forcing an unload.
+		 */
+		error = EBUSY;
+		break;
+
 	case MOD_SHUTDOWN:
 		break;